rampart

a high wide wall built for defensive purposes.
A rampart is a high wide wall of earth or stone with a passage on top, for people and small carriages to move about. Walls of this kind, or ramparts, were built in the past to defend a fort or a city from the attack of the enemy.

Though the enemy succeeded in damaging part of the rampart, it was still strong enough to withstand the enemy attack. The enemy after repeated attempts to blast the strong defensive wall gave up the attempt.

The rampart around the historic city fills one with wonder. The strength of the defensive structure is such that it has stood almost intact for the past three centuries.